Jumpering device



June 23, 1942.

2 Sheets-Sheet 1 S. R. SMITH, JR

JUMPERING DEVICE Filed March 20, 1941 m J m Mm m 53w won/Z v A haw s n mH S Jun '23, 1942. s. R. SMITH. an

JUMPERING DEVICE Filed March 20, 1941 2 Sheets-Sheet 2 Inventor: SidngegR Smith Jn,

His Attorney.

Patented June 23, 1942 J UMPERING DEVICE Sidney R. Smith, Jr.,Pittsfield, Mass, assignor to General Electric Company, a corporation ofNew York Application March 20, 19-11, Serial No. 334,375

14 Claims.

The present invention relates to electric circuit interrupting apparatussuch as fuse cutouts,

line sectionalizing switches, and the like, and more particularly toimprovements in jumpering devices for such apparatus.

A common form of electric circuit interrupting apparatus known as areclosing cutout consists essentially of an insulating housing having apair of spaced line terminals and a removable door upon the inner sideof which is mounted a pair of fuses. The cutout also includes amechanism whereby the second fuse is inserted automatically into thecircuit following the blowing of the first fuse as upon the occurrenceof a temporary fault. It is desirable that the blown fuse be replaced bya new one before another fault results in a service interruption by theblowing of the second fuse. In renewing the blown fuse it is the generalpractice to make a jumper connection across the line leads whereupon thedoor of the cutout may be removed without interrupting the load current.

It is an object of the present invention to provide a new and improvedmaintenance device for effecting a jumper connection across the lineterminals of a cut-out or the like apparatus which device is easy andsafe to manipulate.

It is a further object of the present invention to provide a jumperingdevice which is light in weight, comprises a relatively few parts andwhich may be manufactured at a relatively low cost.

It is a further object of the invention to provide an improvedmaintenance device which may be employed for servicing sectionalizingswitches, reclosing fuse cut-outs and like forms of interruptingdevices.

In accordance with one form of the invention an insulating handle isprovided with a pair of laterally extending and relatively movable prongcontacts. The prong contacts are electrically interconnected and adaptedfor insertion into suitable openings through a side wall of a switch orcutout casing and into engagement with the line terminals therein. Thespacing of the prong contacts is adjusted by meansincluding the handleand in such a manner that the jumper connection is maintained firmlybetween the line terminals during the servicing operation of the switchdevice.

Further objects and advantages of the invention will appear from thefollowing description and the claims appended thereto taken inconnection with the accompanying drawings.

In the drawings, Fig. 1 is a front elevation partly in section of anelectric switch device the line terminals of which are interconnected bya jumpering device constructed in accordance with one form of thepresent invention; Fig. 2 is an enlarged longitudinal cross-sectionalview of the jumpering device shown in Fig. 1; Fig. 3 is a longitudinalcross-sectional view of a jumpering device constructed in accordancewith a second modification; Fig. 4 is another sectional viewillustrating a still further modification of the invention; Fig. 5 is aview taken on line 5-5 of Fig. 4; and Fig. 6 is a view partly in sectionshowing a particular operating position of the jumpering device of Fig.4.

Referring to Fig. 1, an electric circuit interrupting device is showncomprising an insulating casing I0 having a pair of space line terminalsII and 12 mounted therein and electrically connected to the line leads I3 and I4, respectively. Normally closing the open front of the casing isa removable door i5 upon the inner side of which is mounted a circuitinterruting unit, not shown, for interconnecting the line terminal IIand i2 and which, for example, may comprise a pair of fusible elementsand an automatic reclosing mechanism.

For bridging the line terminals l i and [2 of the circuit interruptingdevice so that the cover l5 may be removed for replacement of a blownfuse or other servicing operation without interrupting the circuit, Iprovide a jumpering device generally indicated at I 6. This device isprovided with a pair of electrically interconnected contact prongs whichare adapted for insertion into openings l3 and 20, respectively, in aside wall of the cutout casing l0 and for engagement with the adjacentspaced line terminals H and I2, respectively.

In the embodiment of the invention illustrated in Fig. 2, the jumperingdevice comprises a round, longitudinal handle 25 of a suitableinsulating material such as wood, having a pair of spaced, relativelymovable metal prong contacts 25 and 21 mounted on one end thereof andextending laterally with respect thereto. One contact 26 is formedintegrally with the cylindrical portion 28 of substantially the samediameter as the handle 25, the portion 28 being provided with a ferrule29 for cooperatively fitting over the reduced end portion 3| of thehandle 25 and which is secured thereto by means of a through rivet 32.The upper contact 2'! is formed integrally with a cylindrical portion 33which is also of substantially the same diameter as the round handle 25and is arranged within the upper end of the insulating tube 34. Theinsulating tube 34 may be of any suitable material such as fiber andextends concentrically downwardly over the round handle 25, the innerdiameter of the tube being just slightly greater than the outer diameterof the handle 25 50 that the tube 36 may be moved freely longitudinallyover the handle. The tube 34 is provided with a longitudinal slot 35along one side at the upper end thereof of a width substantially equalto the thickness of the prong contacts 255 and 21, and through which thecontacts extend and are thereby maintained in an aligned relation.

The contacts 26 and 27 are electrically interconnected such as, forexample, by the flexible conductor 31 the opposite ends of which may besoldered or swaged into the sleeve portions 38 and 38 of the contacts 26and H, respectively. The contacts are biased apart by means of acompression spring 4| arranged within the tube 34 and engaging thefacing surfaces of the cylindrical portions 23 and 33 of the twocontacts. A stop pin 42' is arranged across the upper end of the tube 34above the cylindrical portion 33 of the upper contact and suitablysecured as by peening over the opposite ends thereof.

A rubber bumper 43 secured in a cooperating hole in the lower contactportion 28 is arranged between the lower end of the slot 35 of tube 34and the lower contact 26.

The jumpering device described may be operated by holding the handle atan angle with respect to the side of the cutout casing and inserting theupper contact into the upper hole 19 in the cutout casing. Then bypushing up on the lower end of the handle 25, the spacing between thetwo contacts may be adjusted, the lower contact brought into a positionadjacent the lower cutout casing hole and inserted therein. Afterinsertion of the jumper contacts into the openings of the cutout casingand release of the handle 25, the compression spring M will force thecontact prongs apart into a wedging engagement with the line contactsand effectively secure the jumpering device in position while the cutoutis being serviced. It will be observed that the contact prongs 28 and 21are angularly disposed with respect to the longitudinal axis of thehandle and divergently with respect to each other so that upon insertionof the contacts into the casing openings 19 and 20 of the circuitinterrupter, the opposite sloping surfaces of the prongs will engagewith the inner corners 14 and 55 of the casing openings so that underthe force of the spring 4| the ends of the contact prongs will tend tobe forced with a wedging action against the line terminals H and I2 ofthe circuit interrupter.

In the modification illustrated in Fig. 3, the jumpering devicecomprises a longitudinal insulating handle 50 upon the upper end ofwhich is mounted the spaced and relatively movable prong contacts 5| and52 which, as in the previous modification, extend laterally from oneside of the handle. The contact 52 is formed integrally with a hollowcylindrical member 53 which extends coaxially from the end of the handle59. The upper contact 5! is formed integrally with a cylindrical portion54 which is axially movable within the cylindrical member a longitudinalslot 55 being provided in the upper end of the cylinder 53 through whichthe contact 5! extends in alignment with the contact 52. The cylindricalportion 5 3 of the upper contact 5| is cooperatively threaded upon the:

screw 53 the opposite end 57 of which is fixedly secured in the upperend of the handle 58 as by means of a through rivet 58. Arranged aroundthe screw 56 and within the cylinder 53 between the lower surface of theupper contact portion 54 and the upper surface of the sleeve 59, whichis fixed in the lower end of the cylinder 53 as by pins 69, is acompression spring 6| biasing the contacts 5! and 52 apart and biasingsleeve 53 against the upper end surface of handle 5G. An insulatingsleeve 62 is slid over the cylinder 53, having a slot 63 coinciding withthe cylinder slot at its upper end and a slit 64 between the lower endand the opening 85 for the contact 52.

In operating this device, the separation of the contacts 5i and 52 isfirst adjusted to the distance between the openings in the cutout casingby turning the handle 5%] while holding the cylindrical portion 53stationary as by insertion of the lower prong 52 into the correspondingcutout casing opening. The upper contact prong is then inserted into theupper opening in the side of the cutout casing and the handle 50 isrotated in the proper direction so as to move the contacts 5'! and 52relatively toward each other. It will be observed that the ends of thecontacts are bent toward each other by a slight angle so that when thecontacts are moved together, the facing sloping surfaces thereof willengage with the inner edges of the casing openings, to force the ends ofthe contact prongs with a wedging action against the adjacent surfacesof the line terminals. In this manner not only is a good contact assuredbetween the line terminals but also the jumpering device is securelyheld in position while the circuit interrupter is being serviced.

In the further modification of the invention illustrated in Figs. 4 to6, inclusive, a more compact device is provided which has in place of along operating handle, a relatively small insulating cover by which thedevice may be operated. In this device, the jumper connection element isalso pivotally mounted within the cover so that it may be snapped intothe side openings of the cutout box by a pressure exerted laterally ofthe device. The device is held in place by means of a suitable springand an over-center arrangement of the pivotal supporting linkage. Theinsulating cover H may be of any suitable molded insulating material andhas an operating handle 12 and an open side is opposite the handle 12.For eifecting a jumper connection between the line terminals H and [2 ofthe cutout ill, a jumpering element M is arranged within the casing Hcomprising essentially a pair of contact prongs l5 and 18 having theirends bent towards each other and which are interconnected by a flexibleconductor H. The upper prong I5 is formed integrally with a ferrule 78mounted upon the end of an insulating tube 79. The lower contact prong16 is formed integrally with a metal sleeve 8i) slidably arranged overthe lower end of the tube 19. The upper end of the conductor H isconductively connected to the ferrule 18 in a suitable manner by meansof the nut 8!, while the lower end is connected to the metal sleeve 80by means of the leaf spring clasp 82. The ferrule 78 is provided with adownwardly extending portion 83 the lower end of which is pivotallyconnected by means of a pair of links 84 to the arms of the U-shapedsupport 85. The support 85 is in turn secured to the rear wall of thecasing H as by a screw 86. Outward movement of the upper end of thejumper element 14' is limited by means of stops 8'! formed on the endsof the support arms and which are adapted to be engaged by the links 84in the extended position of the jumper element as shown in Fig. 6. Thelower end of the jumper element is mounted upon the outer end of acurved blade spring 88, the opposite end of which is secured as by ascrew 89 to the rear wall of the insulating casing H. The outer portionof the spring 88 is suitably notched for cooperatively receiving themetal sleeve 88, and the ends of the spring extend through slots formedbetween pairs of bosses 9| provided on diametrically opposite sides ofthe sleeve 80. The spring 88 is so shaped that the ends thereofextending through the slots between the bosses 9| bias the jumperelement 14 in the clockwise direction with regard to the cover H to anoutwardly projecting position as indicated in Fig. 6. In this positionof the jumpering element, the contact prongs 15 and 16 spread somewhatfarther apart than in the collapsed condition of the device andpreferably to the extent that their ends are spaced a distancesubstantially equal to the spacing between the openings l9 and 2D in theside of the cutout I0. After the ends of the contact prongs l5 and havebeen inserted through the side openings in the cutout box, the cover His then pushed toward the cutout box to the position as shown in Fig. 4,by which operation the contact prongs l5 and Hi will be drawn together.In this operation the jumper element 14 will pivot about the end of thespring 88 and the lower pivot of the links 84 will be moved over-centerwith regard to the upper pivot thereof and the supporting point on theend of the spring 88. This pivoting movement of the device within thecover will be accompanied by a downward movement of the tube 13 withinthe sleeve 80 against the bias of the blade spring 88 and, hence also, amovement of the contact prongs 15 and 16 toward each other. The inwardlysloping facing surfaces of the ends of the contact prongs will engagewith the inner edges of the openings [9 and 20 whereby, as in thepreceding modification, the contact prongs will be forced with a wedgingaction against the line terminals H and I2 of the cutout. Upon movementof the lower pivot of the links 84 past the overcenter position, tothatshown in Fig. 4, the upward bias of the blade spring 88 will act tohold the jumpering device firmly in the position shown. A stop formed byshoulder 93 on the upper end of portion 83 is adapted to engage with thelower edge of the bracket arms 85 to limit the movement of the jumperelement 74 towards the rear wall of the cover as th links 84 are snappedpast their overcenter position. By simply pulling out on the handle 12and rocking the lower pivot of the links 84 past the overcenter positionagainst the bias of the spring 88, the contact prongs will again bespread apart enabling the withdrawal of the jumpering device from thecutout box.

An additional advantage of the last described modification of theinvention is that the flexible conductor Tl may be replaced by aconventional type of fuse link of a low rated capacity for in\terrupting small load currents. The device may therefore be used as anauxiliary circuit interrupting means and when so equipped and attachedto the side of a cutout box in the manner shown, the regular door withthe attached fuses may be withdrawn from the cutout to transfer the loadcurrent to the small fuse link to the jumper device. The latter fuselink will be melted and the resultant arc will be immediatelyinterrupted by expulsion action. It will be observed that the cover H isopen at the bottom end so that the arc gases may be discharged freelyfrom the lower end of the expulsion tube.

Having described my invention in what I consider to represent preferredembodiments thereof, I desire to have it understood that the specificforms shown are merely illustrative and that the invention may becarried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A jumpering device for interconnecting a pair of terminals of anelectrical device comprising an insulating handle, a pair of spacedrelatively movable contacts mounted on said handle, means electricallyinterconnecting said contacts, and means including said handle formoving one of said contacts relative to the other.

2. A jumpering device for interconnecting a pair of terminals of anelectrical device comprising an insulating handle, a pair of spacedrelatively movable contact prongs mounted on said handle and extendinglaterally with respect thereto at one end thereof, means electricallyinterconnecting said contact prongs, and means including said handle formoving one of said contact prongs relative to the other.

3. A jumpering device for interconnecting a pair of terminals of anelectrical device comprising a longitudinal insulated handle, a pair ofspaced laterally extending contacts mounted on one end of said handle,one of said contacts being movable longitudinally with respect to saidhandle, means for maintaining said movable contact in alignment with theother of said contacts, and means including said handle for shiftingsaid movable contact relative to the other.

4. A jumpering device for interconnecting a pair of terminals of anelectrical device comprising a longitudinal insulating handle, a pair ofspaced relatively movable contacts having angularly disposed prongsextending laterally of said handle and mounted on one end thereof,spring means arranged between said contacts for biasing said contactsapart, means including an insulating sleeve around said handle forengaging said movable contacts and forcing said contacts together.

5. A jumpering device for interconnecting a pair of terminals of anelectrical device comprising a longitudinal insulating handle, a pair ofspaced relatively movable contacts extending laterally from one end ofsaid handle, guide means for maintaining said contacts in a predetermined alignment, and means including said guide means for moving oneof said contacts relative to the other.

6. A jumpering device for interconnecting a pair of terminals of anelectrical device comprising a longitudinal insulating handle, a pair ofspaced relatively movable contacts mounted on one end of said handle andextending laterally with respect thereto, means for maintaining saidcontacts in alignment, a screw secured to said handle and cooperativelythreaded into one of said contacts whereby the separation between saidcontacts may be adjusted by rotational movement of said handle.

'7. In combination with an electric circuit interrupting deviceincluding an insulating casing having a pair of spaced line terminalsmounted therein and openings in said casing adjacent said terminals, ajumpering device having a pair of spaced contact prongs, meanselectrically interconnecting said contact prongs, an insulating supportfor said contact prongs, said contact prongs being relatively movableon'said support with respect to each other, means on said support foradjusting the spacing between said contact prongs, said contact prongsbeing of a length sufficientto engage said spaced line terminalsthroughsaiol casing openings.

8. In combination with an electric circuit interrupting device includingan insulating casing having a pair of spaced line terminals mountedtherein and openings in said casing adjacent said terminals, anauxiliary electric device having a pair of spaced terminals, meanselectrically interconnecting said spaced terminals, an insulatingsupport for said spaced'terminals, means including said'support foradjusting the separation between said spaced terminals, said terminalsbeing anguiarly disposed with respect to each other and to said support,said terminals being adapted for insertion into said casing openings,said terminals being furthermore adapted to engage with portions of saidsing adjacent said openings whereby adjustment of said su port willforce said spaced terminals into wedging contact with said spaced lineterminals.

9. In combination with an electric circuit interrupting device includingan insulating casing having a pair of spaced line terminals mountedtherein and openings in said casing adjacent said line terminals, anauxiliary electric device having a pair of spaced contact prongs, aninsulating support for said contact rongs, means electricallyinterconnecting said contact prongs, one of said contact prongs beingmovable with respect to the other, said contact prongs being an gularlydisposed with respect to each other and with respect to said support,said contact prongs being adapted for insertion into'said casingopenings and to engage with portions of said casing in said openingswhereby movement of said prongs relative to each other by actuation ofsaid support will force said contacts into engagement with said spacedline terminals.

10. A jumper device for attachment to a cutout or like apparatus havinga pair of spaced terminals adjacent openings through a wall of aninsulating housing therefor, said device comprising an insulating cover,a pair of contact prongs for insertion through said openings intoengagement with said terminals, a support for said contact prongs, saidcontact prongs being relatively movable with respect to each other on.said support, and means for adjusting said contact prongs to secure saiddevice to said housing.

11. A jumper device for attachment to a cutout or like apparatus havinga pair of spaced terminals adjacent openings through a wall of aninsulating housing therefor, said device comprising an insulatinghandle, a pair of contact prongs for insertion through said openingsinto engagement with said terminals, said contact prongs being mountedfor movement relative toward each other on said handle, the ends of saidcontact prongs being bent at an angle with respect to each other, meansfor effecting movement of said contact prongs relative to each otherfollowing insertion thereof through said openings, the sloping surfacesof the ends of said contact prongs engaging with the inner corners ofsaid housing Wall whereby said contact prongs are forced with a wedgingaction against said spaced terminals.

12. A jumper device for attachment to a cutout or like apparatus havinga pair of spaced ter minals adjacent openings through a wall of aninsulating housing therefor, said device comprising an insulating cover,a pair of contact prongs for insertion through said openings intoengagement with said terminals, a support for said contact prongs, saidcontact prongs being relatively slidable toward each other on saidsupport, springmeans normally biasing said support away from said cover,an overcen'ter linkage securing one end of said support to said cover,said 5 ring means and said linkage being so arranged whereby said deviceis held attached to said housing when said contact prongs are insertedthrough said openings and said cover portion toward said housing.

13. A jumper device for attachment toa cutout or like apparatus having apair of spaced terminals adjacent openings through a wall of aninsulating housing therefor, said device comprising an insulating cover,a pair of contact prongs for insertion through said openings intoengagement with said terminals, a flexible conductor connecting saidpair of contact prongs, a support for said contact prongs, said contactprongs be ing relatively movable toward each other on said support,means for mounting said support in said cover whereby said device isheld attached to said housing when said contact prongs are insertedthrough said openings and said cover pushed toward said housing.

14. A jumper device for attachment to a cutout or like apparatus havinga pair of spaced terminals adjacent openings through a Wall of aninsulating housing therefor, said device comprising an insulating cover,a pair of contact prongs for insertion through said openings intoengagement with said terminals, a flexible conductor connecting saidcontact prongs, a support for said contact prongs, said contact prongsbeing relatively slidable toward each other on said support, overcenterlinkage means mevably supporting one of said contact prongs 011 saidcover, spring means pivotally supporting the other of said contactprongs upon said cover, said spring means normally biasing said contactsupport away from said .cover said spring means and said linkage beingfurthermore so arranged whereby said device is held attached to saidhousing when said contact prongs are inserted through said openings andsaid cover pushed toward said housing.

SIDNEY R. SMITH, JR.

